Generally, the spacer grids for nuclear reactor fuel claddings are required to exhibit high tensile strength and corrosion resistance, and accordingly some zirconium alloys have recently been used in producing such spacer grids.
An example of such a zirconium alloy is described in Japanese Patent Public Disclosure No. 13550/1987, which is comprised, on a weight percent basis of 0.5-10% Nb, 0.01-5% of one or more elements selected from the group consisting of Fe, Cr, Ni, V, Mn, Mo, C and Si and the remainder Zr and incidental impurities, and another zirconium alloy is described in Japanese Patent Public Disclosure No. 140678/1983, which is comprised, on a weight percent basis of 5-25% Nb, 0.1-1% of Fe and/or Cr, the remainder Zr and incidental impurities.
As the spacer grids for nuclear reactor fuel claddings are usually constructed by welding of the Zr alloy members, the tensile strength and the corrosion resistance at the welded zone deteriorates, resulting in a relatively short life span thereof.
With a view to improving the conventional Zr alloy so as to be capable of maintaining its tensile strength and corrosion resistance even after it has been welded to form spacer grids, efforts are being made to develop a novel alloy which does not show any deterioration in its tensile strength and corrosion resistance.
As a result of such efforts, the inventors of the present invention have found that such an alloy may be produced by adding Nb and one or more components selected from the group consisting of Y and rare earth elements and oxides thereof, and optionally one or more elements selected from the group consisting of Fe, Cr, Mo and V to the conventional Zr alloy.